70+ Application Developer Interview Questions and Answers for Freshers

Multitasking is the ability of an operating system to run multiple tasks concurrently while multiprogramming is the ability to run multiple programs concurrently.

• Multitasking allows multiple tasks to run concurrently on a single processor system.

• Multiprogramming allows multiple programs to run concurrently on a single processor system.

• Multitasking is achieved through time-sharing, where the processor switches between tasks at a very high speed.

• Multiprogramming is achieved thr...read more

Query to find 3rd highest salary from each department

• Use window functions like ROW_NUMBER() to rank salaries within each department

• Filter the results to only include rows where the rank is 3

• Group by department to get the 3rd highest salary for each department

Inner join returns only the matching records from both tables, while outer join returns all records from both tables.

• Inner join combines rows from two tables based on a related column.

• Outer join combines rows from two tables, including unmatched rows.

• Inner join returns only the matching records from both tables.

• Outer join returns all records from both tables, filling in NULL values for unmatched rows.

• Example: Inner join of 'Customers' and 'Orders' tables will return only the ...read more

Quality testing is performed to ensure that software meets the required standards and functions correctly.

• Quality testing involves various techniques such as functional testing, performance testing, security testing, and usability testing.

• Functional testing checks if the software meets the specified requirements.

• Performance testing evaluates the software's speed, scalability, and stability under different conditions.

• Security testing identifies vulnerabilities and ensures data...read more

Answers to questions related to application development

• String is immutable because it cannot be changed once created. Any modification creates a new object.

• Arrays are fixed in size while ArrayLists can dynamically grow and shrink.

• OOP concepts include encapsulation, inheritance, and polymorphism.

• SQL queries are used to retrieve, insert, update, and delete data from a database.

Circular doubly linked list is a data structure where each node has a reference to both the next and previous nodes, forming a circular loop.

• Create a Node class with data, next, and prev pointers

• Implement operations like insert, delete, search, and display

• Ensure the last node's next pointer points to the first node and the first node's prev pointer points to the last node

Searching and sorting algorithms are essential in programming for efficiently organizing and retrieving data.

• Searching algorithms: linear search, binary search, depth-first search, breadth-first search

• Sorting algorithms: bubble sort, selection sort, insertion sort, merge sort, quick sort

• Examples: Searching for a specific item in a list, sorting a list of numbers in ascending order

Program to remove duplicates in a string

• Create an empty array to store unique characters

• Iterate through each character in the string

• Check if the character is already in the array, if not add it

SMPS stands for Switched-Mode Power Supply.

• It is an electronic power supply that uses a switching regulator to convert electrical power efficiently.

• It is commonly used in computers, TVs, and other electronic devices.

• It is smaller and lighter than traditional linear power supplies.

• It can operate at high frequencies, reducing the size of transformers and capacitors.

• It is more energy-efficient than linear power supplies.

• Examples include the Mean Well LRS-350-12 and the Delta Ele...read more

To compare 2 files in file handling, read both files line by line and compare each line.

• Read both files line by line

• Compare each line of the files

• Handle cases where files have different number of lines

• Use file handling functions like fopen, fgets, and fclose

To deactivate a trigger in production, you can use the ALTER TRIGGER statement to disable the trigger.

• Use the ALTER TRIGGER statement with the DISABLE option to deactivate the trigger.

• Make sure to test the trigger deactivation in a non-production environment before applying it to production.

• Document the trigger deactivation process for future reference and troubleshooting.

Abstraction focuses on hiding the implementation details, encapsulation bundles data and methods together, and interfaces define a contract for classes to implement.

• Abstraction: Hides the implementation details and only shows the necessary features. Example: Car class with start() and stop() methods without showing the internal engine workings.

• Encapsulation: Bundles data and methods together within a class, preventing direct access from outside. Example: Private variables wit...read more

Python is used for data science due to its simplicity, readability, extensive libraries, and community support.

• Python is easy to learn and read, making it accessible for beginners and experts alike

• Python has a wide range of libraries like NumPy, Pandas, and Scikit-learn for data manipulation and analysis

• Python has a strong community support with active forums and resources for data science enthusiasts

• Python's versatility allows for integration with other tools and languages c...read more

AWS offers a wide range of cloud services for various purposes.

• Compute services: EC2, Lambda

• Storage services: S3, EBS

• Database services: RDS, DynamoDB

• Networking services: VPC, Route 53

• Security services: IAM, KMS

• Analytics services: Redshift, EMR

• AI/ML services: SageMaker, Rekognition

Tcode for BADI is SE18. To find a BADI, use transaction code SE18 and enter the BADI name or filter by application area.

• Tcode for BADI is SE18

• To find a BADI, use transaction code SE18

• Enter the BADI name or filter by application area

Encapsulation focuses on hiding the internal state of an object and restricting access to it, while polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Encapsulation helps in achieving data hiding and abstraction by restricting access to certain components of an object.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass, enabling flexibility and extensibility in code.

• Encapsulation is imp...read more

Lambda function is an anonymous function in Python that can have any number of arguments, but can only have one expression.

• Lambda functions are defined using the lambda keyword.

• They are commonly used for small, one-time operations.

• Lambda functions can be used as arguments to higher-order functions like map, filter, and reduce.

• Example: add = lambda x, y: x + y

HashSet provides constant time performance for basic operations like add, remove, contains, while ArrayList does not.

• HashSet does not allow duplicate elements, while ArrayList allows duplicates.

• HashSet does not maintain insertion order, while ArrayList maintains insertion order.

• HashSet is faster for checking if an element exists (contains) compared to ArrayList.

SAP MM special procurement processes manage unique purchasing scenarios like consignment and subcontracting.

• Consignment: Stock is owned by the supplier until used, reducing inventory costs.

• Subcontracting: A company provides materials to a vendor who produces finished goods.

• Third-party processing: Goods are shipped directly from the vendor to the customer.

• Pipeline: Materials are procured and transported through a pipeline, often used in oil and gas.

• Make-to-order: Production is...read more

AWS cloud pillars are the foundation of AWS cloud computing services.

• Security - ensuring data protection and privacy

• Reliability - ensuring system availability and fault tolerance

• Performance Efficiency - optimizing resource utilization and scalability

• Cost Optimization - minimizing costs while maximizing benefits

Find the largest element in a window of size K in an array.

• Iterate through the array and maintain a deque to store the indices of elements in decreasing order.

• Remove indices from the front of the deque that are outside the current window.

• The front of the deque will always have the index of the largest element in the current window.

To create a branch, use version control system commands like git branch.

• Use 'git branch' command to create a new branch in Git.

• Specify the branch name after the command, e.g. 'git branch new-feature'.

• To switch to the newly created branch, use 'git checkout new-feature'.

I have used a variety of programming languages including Java, Python, C++, and JavaScript.

• Java

• Python

• C++

• JavaScript

OOP concepts in Java involve encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (class).

• Inheritance: Allowing a class to inherit properties and behavior from another class.

• Polymorphism: The ability for objects of different classes to respond to the same method call.

• Abstraction: Hiding the implementation details and showing only the necessary features of an object.

Hierarchy in Talend refers to the organization of data flow components in a job.

• Hierarchy is important for understanding the flow of data in a job.

• Components can be organized into subjobs and routines for better organization.

• Hierarchy can be viewed and edited in the Talend Studio interface.

• Example: A job may have a parent job with multiple child subjobs for different tasks.

Map transforms each element in an array, while filter creates a new array with elements that pass a test.

• Map: Applies a function to each element and returns a new array. Example: [1, 2, 3].map(x => x * 2) results in [2, 4, 6].

• Filter: Returns a new array with elements that meet a condition. Example: [1, 2, 3].filter(x => x > 1) results in [2, 3].

• Map does not change the original array; it creates a new one. Filter also does not modify the original array.

• Use map when you want to...read more

A synonym is a word or phrase that means the same or nearly the same as another word or phrase in the same language.

• Synonyms are words that have similar meanings.

• They can be used interchangeably in sentences.

• Examples: happy and joyful, big and large, fast and quick.